Des Moines River IA 04-UDM-1220
from confluence with East Fork Des Moines R. (S19 T91N R28W Humboldt Co.) to Humboldt Dam at Lake Nokomis at Humboldt.
- Assessment Cycle
- 2024
- Release Status
- Pending
- Data Collection Period
- Overall IR Category
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Stable
- Created
- 11/1/2023 8:12:59 AM
- Updated
- 1/17/2024 7:38:19 AM
Assessment Summary
The 2020-2022 E. coli data suggest full support of the Class A1 use; however, delisting an impairment requires a monitored assessment. Therefore, the Category 5a Class A1 impairment will remain. The Class BWW1 use was assessed as "fully supported" based on biological sampling data and on water quality monitoring data. The Class HH (fish consumption) use remains assessed as “not supported” due to the existence of a historic one meal per week mercury fish consumption advisory in this segment.
Assessment Explanation
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site
Name Site
Description Iowa DNR 6 WQ CY 2020-2022 10460001 West
Fork Des Moines River near Humboldt
Iowa DNR 6 BIO See Below 933 West
Fork Des Moines River Humboldt Site ID Data Source ID # Samples per Year (2020/ 2021/2022) 2020 Geometric Mean 2021 Geometric Mean 2022 Geometric Mean Violates Annual Geometric Mean? # 2020 SSM violations / SSM Violations needed for impairment # 2021 SSM violations / SSM Violations needed for impairment # 2022 SSM violations / SSM Violations needed for impairment Violates Annual SSM Significantly >10% Rule? Assessment Type Support Level 10460001 6 8/7/8 84 64 87 NO 2 / 3 1 / 3 0 / 3 NO Eval Full The 2020-2022 E. coli data suggest full support of the Class A1 use; however, delisting an impairment requires a monitored assessment. Therefore, the Category 5a Class A1 impairment will remain. Class A1 – pH: Site ID Data Source ID # Samples / # Years Minimum Value Maximum Value Mean Value # Violations Violations needed for impairment Violates Significantly >10% Rule? Assessment Type Support Level 10460001 6 36 / 3 7.1 8.6 8.1 0 7 NO Mon Full Site ID Data Source ID Parameter Name # Samples / # Years Minimum Value Maximum Value Mean Value # Violations # Acute / Chronic Violations Violations needed for impairment Violates Significantly >10% Rule? Assessment Type Support Level 10460001 6 Chloride 36 / 3 11 100 32 NA 0 / 0 7 NO Mon Full 10460001 6 Dissolved Oxygen 36 / 3 7.2 15.5 11.4 0 NA / NA 7 NO Mon Full 10460001 6 pH 36 / 3 7.1 8.6 8.1 0 NA / NA 7 NO Mon Full 10460001 6 Sulfate 36 / 3 53 180 106 0 NA / NA 7 NO Mon Full 10460001 6 Temperature 36 / 3 0 28 12 0 NA / NA 7 NO Mon Full Site ID Data Source ID Parameter Name # Samples / # Years Maximum Value Mean Value Median Value # Acute / Chronic Violations >1 Acute / Chronic Violation Assessment Type Support Level 10460001 6 Ammonia 36 / 3 0.25 0.04 0.02 0 / 0 NO Mon Full 10460001 6 Cadmium 20 / 3 0.5 0.5 0.5 0 / 0 NO Mon Full 10460001 6 Chromium 20 / 3 1 0.59 0.6 0 / 0 NO Mon Full 10460001 6 Lead 20 / 3 1 0.92 1 0 / 0 NO Mon Full 10460001 6 Nickel 20 / 3 3.7 2 1.9 0 / 0 NO Mon Full 10460001 6 Selenium 18 / 2 6 2 2 0 / 1 NO Mon Full 10460001 6 Silver 20 / 3 1 0.902 1 0 / 0 NO Mon Full 10460001 6 Zinc 20 / 3 3.8 0.9 0.5 0 / 0 NO Mon Full Benthic Macroinvertebrates: Site ID Date Drainage Area (mi2) Ecoregion Major Drainage BM Sample Gear BMIBI score BMIBI Class 47b BMIBI BIT BMIBI Pass/Fail 933 7/22/20 2308 47b MS Floating Art Sub 64 Good 62 Pass Community Assessment Type Assessment Result Support Level IR Category Reason Benthic
Macroinvertebrates Evaluated Pass (1/1) Full Assessment was evaluated because the
drainage area Overall Evaluated Pass Full 1 of the site is greater than the calibrated
range. Site ID Data Source ID # Days Monitoring (2016) DO Criteria Type # 2016 violations / Violations needed for impairment Violates Annual Significantly >10% Rule? Assessment Type Support Level 24 hr 0/6 No 933 6 29 16 hr 0/6 No Evaluated Full Support Level Not A historic one
meal/week mercury consumption advisory for any predator fish exists on this
segment. Based on IR Methodology, the Class HH (fish consumption) use was
assessed as “not supported.” Site ID Data Source ID Parameter Name # Samples / # Years Maximum Value Mean Value Median Value Number of Non - Detects Mean Value > Criterion or MCL Assessment Type Support Level 10460001 6 Selenium 18 / 2 6 2 2 1 NO Mon Full
Class A1 - Indicator Bacteria:
Class BWW1 - Binomial Parameters:
Class BWW1 - Toxic Parameters:
Class BWW1 – Biological Sampling:
Overall:
Class BWW1- Continuous DO Monitoring:
Class HH - Fish Tissue Assessment:
Class HH-F - Toxic Parameters:
Assessment Key Dates
7/22/2020 | Biological Monitoring |
1/9/2020 | Monitoring Start |
12/7/2022 | Monitoring End |
Methods
200 | Physical/Chemical Monitoring |
260 | Fish tissue analysis |
315 | Regional reference site approach |
320 | Benthic macroinvertebrate surveys |
420 | Indicator bacteria monitoring |